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This invention is directed to an emulsion of a silicone oil or organic oil, a process for preparing the emulsion, and a process for preparing a silicone oil composition or organic oil composition. More particularly, the invention relates to emulsions which have excellent stability comprising cross-linked particles in drops of silicone or organic oil dispersed in water, and oil compositions with excellent viscoelastic properties and good dispersibility of the cross-linked particles in silicone or organic oils.
Japanese Patent Application Sho 64-81,856 and U.S. Pat. No. 4,980,167 describe a process for preparing cross-linked silicone particles containing a silicone oil by dispersing in water, a cross-linkable silicone composition containing a non-crosslinkable silicone oil, and then carrying out a cross-linking reaction. In another process described in U.S. Pat. No. 4,990,556, cross-linked silicone particles containing an organic oil are produced by dispersing in water, and then cross-linking, a cross-linkable silicone composition which contains a non-crosslinkable organic oil. These methods, however, do not obtain an emulsion of silicone oil or organic oil containing cross-linked particles in drops of silicone oil or organic oil dispersed in water.
Japanese Patent Application Hei 3-271,211 and U.S. Pat. No. 5,760,109, on the other hand describe a process in which an emulsion with cross-linked silicone particles and silicone oil drops in water, is obtained by combining cross-linked silicone particles with a silicone oil emulsion prepared by dispersing silicone oil drops in water. In another known process, an emulsion with organic oil drops and cross-linked silicone particles dispersed in water is produced by combining cross-linked silicone particles with an organic oil emulsion prepared by dispersing organic oil drops in water. In these methods, however, the silicone or organic oil drops and the cross-linked silicone particles are dispersed in water independently from each other, and therefore such methods do not obtain a silicone oil or organic oil emulsion in which cross-linked particles are contained in drops of the silicone oil or organic oil.
Japanese Patent Applications Sho 63-152,308, Hei1 -165,509, and Hei 1-207,354, U.S. Pat. No. 4,987,169, and 7-330,537, describe a silicone oil composition with cross-linked silicone particles dispersed in a silicone oil. Japanese Application Hei 9-136,813 describes an organic oil composition containing cross-linked silicone particles dispersed in an organic oil. This oil composition is produced by mixing a silicone oil with cross-linked silicone particles, or by subjecting a cross-linked product of a cross-linkable silicone composition that contains a non-crosslinkable silicone oil to the action of shearing force. These methods, however, do not obtain a silicone oil composition or an organic oil composition containing cross-linked particles with good dispersibility in the silicone or organic oil.
It is therefore an object of the invention to provide (i) a silicone oil or an organic oil emulsion which possesses excellent stability, and which comprises cross-linked particles in drops of silicone oil or organic oil dispersed in water, (ii) a process for preparing such an emulsion, and (iii) a process for preparing an oil composition with excellent viscoelastic properties and good dispersibility of the cross-linked particles in the silicone oil or organic oil.
These and other features of the invention will become apparent from a consideration of the detailed description.
Not applicable.
The silicone oil or the organic oil emulsion of the invention comprises cross-linked particles which have an average diameter in the range of 0.05 to 100 xcexcm. The particles are cross-linked by hydrosilylating a liquid cross-linkable composition comprising (A) an organic compound having in its molecule at least two aliphatic unsaturated bonds; (B) a silicon-containing organic compound having in its molecule at least two silicon-bonded hydrogen atoms; and (C) a hydrosilylation reaction catalyst. If desired, the liquid cross-linkable composition may also contain D) an organopolysiloxane having at least one alkenyl group in its molecule. The cross-linked particles are contained in drops of silicone oil or organic oil with an average diameter in the range of 0.1 to 500 xcexcm, which in turn are dispersed in water. The diameter of the cross-linked particles is smaller than the diameter of the drops.
The process for preparing emulsions which contain a non-crosslinkable silicone oil or organic oil are obtained by (i) dispersing in water, a liquid cross-linkable composition comprising (A) an organic compound having at least two aliphatic unsaturated bonds in its molecule; (B) a silicon-containing organic compound having at least two silicon-bonded hydrogen atoms in its molecule; (C) a hydrosilylation reaction catalyst; optionally (D) an organopolysiloxane having at least one alkenyl group in its molecule; and a non-crosslinkable silicone oil or organic oil in an amount exceeding the amount of oil that can be held by the product of cross-linking of the liquid cross-linkable composition; and (ii) subjecting the liquid cross-linkable composition to a hydrosilylation reaction. The oil composition is obtained by removing water from the emulsion of silicone oil or organic oil containing the cross-linked particles in drops of the silicone or organic oil.
The emulsion of silicone oil or organic oil comprises cross-linked particles in drops of a silicone oil or organic oil dispersed in water. There are no limitations regarding the type of silicone oil that can be used in the emulsion. For example, the silicone oil may have a linear, partially branched linear, cyclic, or branched molecular structure. A linear or a cyclic molecular structure is preferred. The silicone oil is a material that does not contribute to the hydrosilylation reaction used in forming the cross-linked particles, and some representative oils are dimethylpolysiloxanes having both molecular terminals capped with trimethylsiloxy groups, methylphenylpolysiloxanes having both molecular terminals capped with trimethylsiloxy groups, copolymers of methylphenylsiloxane and dimethylsiloxane having both molecular terminals capped with trimethylsiloxy groups, copolymers of methyl (3,3,3-trifluoropropyl)siloxane and dimethylsiloxane having both molecular terminals capped with trimethylsiloxy groups, cyclic dimethylsiloxanes, cyclic methylphenylsiloxanes, silicone oils having polyether groups, long-chain alkyl groups, epoxy groups, carboxylic groups, ester groups, amido groups, amino groups, or mercapto groups.
There are also no limitations with regard to the type of organic oil used in the emulsion, but it is preferred to use oil compatible with the liquid cross-linkable composition used to form the cross-linked particles. The organic oil may be an aromatic oil or an aliphatic oil having a linear, partially branched linear, cyclic, or branched molecular structure. Organic oils having linear or cyclic molecular structures are particularly preferred. The organic oils may be volatile. The oils should not take part in the hydrosilylation reaction used for forming the cross-linked particles. Some representative organic oils are hexane, heptane, paraffin, isoparaffin, or similar alkanes; toluene, xylene, or similar aromatic compounds; methylisobutylketone or similar ketones; undecyl alcohol or similar alcohols; dibutyl ether or similar ethers; isopropyl laurate, isopropyl palmitate, or similar esters. Volatile alkanes are particularly preferred.
The silicone oil and organic oil can be used in combinations with each other, or they can be used with other components dissolved in them. If the silicone oil or the organic oil is volatile, then by removing the volatile silicone oil or the volatile organic oil and water from the obtained silicone oil or organic oil emulsion, one can obtain a mixture of cross-linked particles with the other components dissolved in a silicone oil or organic oil.
Provided they are soluble in the silicone oil or organic oil, there are no specific limitations with regard to other components which are dissolved in the silicone oil or organic oil, and some representative substances are, for example, silicone resins which are solid at room temperature, silicone oils that are rubber-like at room temperature; carnauba wax, candelilla wax, Japan wax, whale wax, jojoba wax, montan wax, beeswax, lanolin, or similar waxes; liquid paraffin, isoparaffin, hexyl laurate, isopropyl myristate, myristyl myristate, cetyl myristate, 2-octyldodecyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, butyl stearate, decyl oleate, 2-octyldodecyl oleate, myristyl lactate, cetyl lactate, lanolin acetate, stearyl alcohol, cetostearyl alcohol, oleyl alcohol, avocado oil, almond oil, olive oil, cacao oil, jojoba oil, sesame oil, safflower oil, soy oil, White Camellia oil, squalane, persic oil, castor oil, mink oil, cottonseed oil, coconut oil, egg yolk oil, lard, or similar fats and oils; polypropylene glycol monooleate, neopentylglycol-2-ethylhexanoate, or similar glycol ester oils; palm oil fatty acid triglyceride or similar polyhydric alcohol ester oil; polyoxyethylene lauryl ether, polyoxypropylene cetyl ether, or similar polyoxyalkylene ether oil.
There are no specific limitations with regard to the viscosity of the organic oil or the silicone oil used in the emulsion. It is preferred, however, that the viscosity be in the range of 1 mPaxc2x7s to 100,000,000 mPaxc2x7s, preferably 2 to 10,000,000 mPaxc2x7s at 25xc2x0 C. It is also preferred that the drops of silicone oil or organic oil used in the emulsion have an average diameter in the range of 0.1 xcexcm to 500 xcexcm, preferably 0.2 xcexcm to 500 xcexcm, and more preferably 0.5 xcexcm to 500 xcexcm, with 0.5 xcexcm to 200 xcexcm being especially preferred. If the diameter of the oil drops is smaller than the lower limit of the range, the preparation of the emulsion is difficult. If the diameter of the drops exceeds the upper limit of the range, the emulsion has low stability.
Cross-linked particles used in the emulsions are obtained by subjecting to hydrosilylation, a liquid cross-linkable composition comprising (A) an organic compound having at least two aliphatic unsaturated bonds in its molecule; (B) a silicon-containing organic compound having at least two silicon-bonded hydrogen atoms in its molecule; (C) a hydrosilylation reaction catalyst; and optionally (D) an organopolysiloxane having at least one alkenyl group in its molecule.
Organic compounds that represents component (A) are characterized by having in their molecule at least two aliphatic unsaturated bonds such as a vinyl group, allyl group, butenyl group, pentenyl group, or similar alkenyl group; an ethynyl group or similar alkynyl group; a norbornene, dicyclopentadienyl, or similar cyclic unsaturated terminal or side-chain group; a vinylene group, propenylene group, or similar ethylene group inside the main molecular chain. Most preferred are a vinyl group or an allyl group. There are no specific limitations with regard to the form of component (A), and it may be a solid or liquid, although liquids are preferred. If component (A) is a solid, it should be dissolved in another component or in an organic solvent capable of dissolving component (A). There are no limitations with regard to the molecular weight of component (A), but it is preferred that the average molecular weight be in the range of 50 to 50,000.
Some examples of compounds suitable for use as component (A) are pentadiene, hexadiene, heptadiene, octadiene, nonadiene, cyclopentadiene, cyclooctadiene, or similar dienes; divinylbenzene or similar aromatic dienes; diallyl ether, triethylene glycol divinyl ether, cyclohexadimethanol divinyl ether, 1,2-divinylglycol, or similar ether; diallyl isophthalate, diallyl phthalate, diallylterephthalic acid, diallylmaleate, triallyltrimellitate, or similar diene; an oligomer obtained by polymerizing the aforementioned compounds; an olefin oligomer which is obtained by polymerizing ethylene, propylene, butene, isobutene, pentene, hexene, or similar olefin, and which contains a group with at least two aliphatic unsaturated bonds; an oligomer obtained by polymerizing acrylic monomers with acrylic groups such as allyl methacrylate, butenyl methacrylate, methylbutenyl methacrylate, methylpropenyl methacrylate, heptenyl methacrylate, and hexenyl methacrylate; an oligomer obtained by copolymerizing the aforementioned acrylic monomers with other monomers such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylhexyl methacrylate, lauryl methacrylate, styrene, xcex1-methylstyrene, maleic acid, vinyl acetate, allyl acetate, or similar monomer; an oligomer obtained by reacting a carboxylic acid anhydride which contains an alkenyl group such as allyl isocyanate, methacryloyl isocyanate, or 2-isocyanate ethyl methacrylate, with an oligomer obtained by copolymerizing the aforementioned monomers with an acrylic monomer containing a hydroxyl group such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate; an oligomer obtained by reacting an alkenyl alcohol such as allyl alcohol, butene diol, 2-(allyloxy) ethanol, glycerol diallyl ether, cyclohexene methanol, methyl butynol, oleyl alcohol, or similar alkenyl alcohol; an oligomer obtained by reacting an epoxy compound that contains an alkenyl group such as glycidyl methacrylate or allyl glycidyl ether with an oligomer obtained by copolymerizing the aforementioned monomers with an oligomer obtained by polymerizing methacrylic acid, itaconic acid, maleic acid, or similar monomer that contains a carboxyl group; or an oligomer obtained by copolymerizing the aforementioned monomers with the monomer that contains a carboxy group; a polyether obtained by the ring-opening polymerization of allyl glycidyl ether using ethylene glycol as an initiator or a polyether obtained by the ring-opening polymerization of vinyl-cyclohexane-1,2-epoxide using propargyl alcohol as initiator; a polyester that contains alkenyl groups obtained by reacting the aforementioned alkenyl alcohols with a polyhydric alcohol such as ethylene glycol, propylene glycol, 1,6-hexane diol, diethylene glycol, neopentyl glycol, the ester of neopentyl glycol hydroxy pivalinate, or trimethylol propane, with a polybasic acid such as phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, azelaic acid, or trimellitic acid. Most preferred are dienes, diene oligomers, or polyethers.
Component (B) is a silicon containing organic compound having at least two silicon-bonded hydrogen atoms. There are no specific limitations with regard to the viscosity of component (B). It is preferred, however, that the viscosity be in the range of 1 mPaxc2x7s to 100,000 mPaxc2x7s, preferably 1 to 10,000 mPaxc2x7s at 25xc2x0 C. Component (B) can be an organohydrogenpolysiloxane or an organic polymer that contains a diorganohydrogensilyl group. An organohydrogenpolysiloxane is preferred.
The organohydrogenpolysiloxane can have a linear, branched, cyclic, network, or linear partially branched molecular structure. Some representative examples of such polysiloxanes are methylhydrogenpolysiloxanes having both molecular terminals capped with trimethylsiloxy groups, copolymers of methylhydrogensiloxane and dimethylsiloxane having both molecular terminals capped with trimethylsiloxy groups; copolymers of methylphenylsiloxane, methylhydrogensiloxane, and dimethylsiloxane having both molecular terminals capped with trimethylsiloxy groups; copolymers of methylphenylsiloxane, dimethylsiloxane having both molecular terminals capped with dimethylhydrogensiloxy groups, and dimethylpolysiloxane having both molecular terminals capped with dimethylhydrogensiloxy groups; methylphenylpolysiloxanes with both molecular terminals capped with dimethylhydrogensiloxy groups; an organopolysiloxane copolymer composed of R3SiO1/2 units, R2HSiO1/2 units, and SiO4/2 units; an organopolysiloxane copolymer composed of R2HSiO1/2 units and SiO4/2 units; an organopolysiloxane copolymer composed of RHSiO2/2 units, RHSiO3/2 units, HSiO3/2 units; and mixtures of two or more of such organopolysiloxanes. R in such units represents a univalent hydrocarbon group other than an alkenyl group, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, or similar alkyl groups; phenyl, tolyl, xylyl, naphthyl, or similar aryl groups; benzyl, phenethyl, or similar aralkyl groups; and chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, or similar halogenated alkyl groups.
When component (B) is an organic polymer containing a diorganohydrogensilyl group, it can be an oligomer obtained by copolymerization of an acrylic monomer having dimethylhydrogensilyl groups such as dimethylhydrogensilyl methacrylate and dimethylhydrogensilylpropyl methacrylate, with a monomer represented by methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylhexyl methacrylate, lauryl methacrylate, styrene, xcex1-methylstyrene, maleic acid, vinyl acetate, and allyl acetate.
It is preferred that the content of component (B) in the liquid cross-linkable composition be in the range of 0.1 parts by weight to 500 parts by weight, preferably 0.5 to 500 parts by weight, and more preferably 1 to 100 parts by weight. If the content of component (B) is below the lower limit of the range, the liquid cross-linkable composition may not be sufficiently crosslinked. If the content of component (B) exceeds the upper limit of the range, an excess of silicon-bonded hydrogen atoms may generate gaseous hydrogen.
Component (C) is a hydrosilylation reaction catalyst used for accelerating the hydrosilylation reaction and for cross-linking the liquid cross-linkable composition. It can be a platinum catalyst, a rhodium catalyst, or a palladium catalyst, but a platinum catalyst is preferred. The platinum catalyst can be in the form of platinum on fine silica powder, platinum on fine carbon powder, chloroplatinic acid, an alcoholic solution of chloroplatinic acid, a platinum olefin complex, a platinum alkenylsiloxane complex, or a platinum carbonyl complex.
There are no specific limitations on the content of component (C) in the liquid cross-linkable composition provided it is sufficient for accelerating the hydrosilylation reaction of the liquid cross-linkable composition. It is preferred that when a platinum catalyst is used as component (C), it should be present in an amount of from 1xc3x9710xe2x88x927 parts by weight to 1xc3x9710xe2x88x923 parts by weight, based on 100 parts by weight of the sum of components (A) and (B), or the sum of components (A), (B), and (D). If component (C) is used in an amount smaller than the lower limit of the range, there is risk of insufficient cross-linking. If component (C) is present in an amount exceeding the upper limit of the range, it will be economically inefficient.
Organopolysiloxane component (D) is an optional component of the liquid cross-linkable composition. It contains at least one alkenyl group in its molecule and can be used either for improving the affinity of obtained cross-linked particles for the silicone oil, or for imparting flexibility and rubber elasticity. It is preferred that component (D) be an organopolysiloxane having at least two alkenyl groups in its molecule. The alkenyl group of component (D) may be group such as vinyl, allyl, butenyl, pentenyl, and hexenyl, but vinyl is preferred. Silicon atom-bonded groups other than alkenyl groups in component (D) are univalent hydrocarbon groups such as methyl, ethyl, propyl, butyl, or similar alkyl groups; cyclopentyl, cyclohexyl, or similar cycloalkyl groups; phenyl, tolyl, xylyl, or similar aryl groups; benzyl, phenethyl, 3-phenylpropyl, or similar aralkyl group; 3-chloropropyl, 3,3,3-trifluoropropyl, or similar halogenated hydrocarbon group. Component (D) may be linear, branched, cyclic, network, or partially-branched linear. A linear structure is preferred. There are no specific limitations on the viscosity of component (D), however, it is preferred that it be from 20 mPaxc2x7s to 100,000 mPaxc2x7s, preferably 20 to 10,000 mPaxc2x7s at 25xc2x0 C.
Some representative examples of component (D) are copolymers of methylvinylsiloxane and dimethylsiloxane having both molecular terminals capped with trimethylsiloxy groups, methylvinylpolysiloxanes having both molecular terminals capped with trimethylsiloxy groups, copolymers of methylphenylsiloxane, methylvinylsiloxane, and dimethylsiloxane having both molecular terminals capped with trimethylsiloxy groups, dimethylpolysiloxanes having both molecular terminals capped with dimethylvinylsiloxy groups, methylvinylpolysiloxanes having both molecular terminals capped with dimethylvinylsiloxy groups, copolymer of methylvinylsiloxane and dimethylsiloxane having both molecular terminals capped with dimethylvinylsiloxy groups, copolymers of methylphenylsiloxane, methylvinylsiloxane, and dimethylsiloxane having both molecular terminals capped with dimethylvinylsiloxy groups, organopolysiloxane copolymers containing R3SiO1/2 siloxane units, R2R1SiO1/2 siloxane units, and SiO4/2 siloxane units, organopolysiloxane copolymers composed of siloxane units R2R1SiO1/2 and siloxane units SiO4/2, organopolysiloxane copolymers composed of siloxane units RR1SiO2/2, siloxane units RSiO3/2, and siloxane units R1SiO3/2. These organopolysiloxane units can be present in combinations of two or more. R in the units represents a univalent hydrocarbon group other than alkenyl, and is the same as the groups referred to above. R1 is an alkenyl group such as vinyl, allyl, butenyl, pentenyl, hexenyl, and heptenyl.
Component (D) should be present in the liquid cross-linkable composition in such an amount that the weight ratio of component (A) to component (D) is in the range of from 0.1:99.9 to 99.9:0.1, preferably 0.5:99.5 to 50:50. If component (D) is present in an amount exceeding the upper limit of the range, obtained cross-linked particles exhibit a tendency towards decreased affinity for organic oils. If the content is below the lower limit of the range, obtained cross-linked particles have a decreased affinity for silicone oils.
In addition to components (A) to (D), the liquid cross-linkable composition may contain other components such as reaction inhibitors for regulating hydrosilylation reactions; reinforcing fillers such as precipitated silica, fumed silica, calcined silica, fumed titanium oxide; non-reinforcing fillers such as powdered quartz, diatomaceous earth, alumosilicic acid, iron oxide, zinc oxide, calcium carbonate; and fillers obtained by surface-treating any of the previous fillers with organosilicon compounds such as hexamethylsilazane, trimethylchlorosilane, polydimethylsiloxane, or polymethylhydrogensiloxane.
The liquid crosslinkable composition should be crosslinked by a hydrosilylation reaction to form a rubber-like, gel-like, or elastomer-like, or resin-like cross-linked product.
The average diameter of the cross-linked particles in the emulsion of the invention should be in the range of 0.05 xcexcm to 100 xcexcm, preferably 0.1 xcexcm to 100 xcexcm, and more preferably 0.1 xcexcm to 50 xcexcm. When the average diameter of the drops of silicone oil or organic oil is in the range of 0.2 xcexcm to 500 xcexcm, the cross-linked particles should have an average diameter of 0.1 xcexcm to 100 xcexcm, preferably 0.1 xcexcm to 50 xcexcm. If the average diameter of the drops of silicone oil or organic oil is in the range of 0.5 xcexcm to 500 xcexcm, the cross-linked particles should have an average diameter of 0.1 xcexcm to 100 xcexcm, preferably 0.1 xcexcm to 50 xcexcm. If the drops of silicone oil or organic oil have an average diameter between 0.5 xcexcm and 200 xcexcm, the cross-linked particles should have an average diameter of 0.1 xcexcm to 100 xcexcm, preferably 0.1 xcexcm to 50 xcexcm. If the average diameter of the cross-linked particles is below the lower limit of the preferred range, the preparation of such particles tends to become more difficult. If the diameter of the cross-linked particles exceeds the upper limit of the range, the emulsion exhibits a tendency toward decreased stability. In emulsions of the invention, the cross-linked particles should be smaller in size than the drops of the silicone oil or the organic oil. The cross-linked particles can be spherical, spindle-like, flattened, or irregular in shape, but a spheical shape is preferred.
The are no specific limitations with regard to the amount of silicone oil or organic oil used in emulsions according to invention provided the cross-linked particles are held in the drops of silicone or organic oil. It is preferred however that emulsions be prepared containing the silicone oil or the organic oil in an amount of 50 parts by weight to 5,000 parts by weight, preferably 100 to 5,000 parts by weight, and more preferably 200 to 5,000 parts by weight, based on 100 parts by weight of the liquid cross-linkable composition used to form the cross-linked particles. The most preferred range for the content of the silicone oil or the organic oil is 250 parts by weight to 2,000 parts by weight.
There are no specific limitations with regard to the amount of water that can be used in emulsions according to the present invention. It is preferred however that the amount of water be in the range of 5 weight percent to 99 weight percent, preferably 10 to 80 weight percent, based on the total weight of the emulsion.
The emulsion of the invention may contain a surface-active agent to ensure the stability of the dispersion in water of the drops of silicone oil or organic oil containing cross-linked particles. Representative surface-active agents are cationic surface-active agents such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, tetraalkylammonium salts, trialkylbenzylammonium salts, alkylpyridinium salts, and polyethylene polyamine fatty acid amide salts; anionic surface-active agents such as fatty acid salts, alkylbenzylsulfonic acid salts, alkylnaphthalenesulfonic acid salts, alkylsulfonic acid salts, xcex1-olefinsulfonic acid salts, dialkylsulfosuccinic acid salts, xcex1-sulfonated fatty acid salts, alkylsufuric acid salts, sulfated fats and oils, polyoxyethylene alkyl ether sulfuric acid salts, polyoxyethylene alkylphenyl ether sulfuric acid salts, polyoxyethylene styrenated phenyl ether sulfuric acid salts, alkylphosphoric acid salts, and polyoxyethylene alkylphenyl ether phosphoric acid salts; zwitterionic surface-active agents such as N,N-dimethyl-N-alkyl-N-carboxymethyl ammonium betaine, N,N-dialkylaminoalkylene carboxylic acid salts, N,N,N-trialkyl-N-sulfoalkylene ammonium betaine, and N,N-dialkyl-N,N-bispolyoxyethylene ammonium sulfuric acid ester bentaine; and nonionic surface-active agents such as polyoxyethylene alkyl ether, polyoxyethylene alkenyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polystyrene phenyl ether, polyoxyethylene-polyoxypropylene glycol, polyoxyethylene-polyoxypropylene alkyl ether, sorbitan fatty acid esters, glycerol fatty acid esters, decaglycerol fatty acid esters, polyglycerol fatty acid esters, propylene glycol-pentaerythritol fatty acid esters, propylene glycol-pentaerythritol fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene glycerol fatty acid esters, polyoxyethylene fatty acid esters, polyglycerol fatty acid esters, polyoxyethylenated castor oil, fatty acid diethanolamide, polyoxyethylene alkylamine, triethanolamine fatty acid partial ester, and trialkyleneamine oxides. Most preferred are the nonionic surface-active agents.
There are no specific limitations with regard to the amount of surface-active agent used in the liquid cross-linkable composition. It is preferred however to use 0.1 parts by weight to 20 parts by weight, preferably 0.5 to 10 parts by weight of surface-active agent, based on 100 parts by weight of the silicone oil or the organic oil containing the cross-linked particles.
The emulsion of the present invention can be used as an additive for cosmetics, dyes, and organic resins. The removal of water from the emulsion permits the preparation of a liquid, cream-like, paste-like, or grease-like, silicone oil or organic oil composition containing dispersed cross-linked particles in the silicone or the organic oil. If the oil is volatile, it is then possible (i) to prepare a mixture of cross-linked particles with other components dissolved in the silicone or organic oil by first dissolving the other components in the oil, and then removing water and the volatile oil from the obtained emulsion, or (ii) to prepare cross-linked particles containing organosilicon or other organic compounds which are difficult to incorporate into cross-linked particles.
The process for preparing an emulsion of silicone oil or organic oil according to the present invention is characterized by dispersing in water using a surface-active agent, a liquid cross-linkable composition containing a non-crosslinkable silicone oil or a non-crosslinkable organic oil, and cross-linking the liquid cross-linkable composition by a hydrosilylation reaction. In the process for preparing the emulsion, the non-crosslinkable silicone oil or the non-crosslinkable organic oil do not contribute to cross-linking occurring as a result of the hydrosilylation of the liquid cross-linkable composition.
In accordance with the process for preparing emulsions, the liquid crosslinkable composition consists of components (A)-(C), optionally component (D), and other optional components of the types previously discussed. According to the process, the liquid crosslinkable composition containing a catalyst used for hydrosilylation reactions in water is prepared either (i) by dispersing the liquid crosslinkable composition including component (C) which has been added in advance, or (ii) by dispersing the liquid crosslinkable composition which does not include component (C) in water, and then adding component (C) to the water. In the latter case, it is preferred to add component (C) in the form of an aqueous dispersion with an average particle diameter of not more than about 1 xcexcm.
The non-crosslinkable silicone oil or the non-crosslinkable organic oil contained in the liquid cross-linkable composition should be present in an amount exceeding the amount of non-crosslinkable oil that can be held in the product of cross-linking of the liquid cross-linkable composition. Thus, it should be in excess of the amount of non-crosslinkable silicone oil or organic oil that can be contained in the cross-linked product. The amount will vary depending on the proportions of the liquid cross-linkable composition and the non-crosslinkable silicone or organic oil. In general, however, it is preferred that the non-crosslinkable silicone oil or organic oil be used in an amount of 50 parts by weight to 5,000 parts by weight, preferably 100 to 5,000 parts by weight, more preferably 200 to 5,000 parts by weight, and especially preferably 250 to 2,000 parts by weight, based on 100 parts by weight of liquid cross-linkable composition.
The process for preparing emulsions consists in dispersing in water the liquid cross-linkable composition containing the non-crosslinkable silicone oil or organic oil, and then crosslinking the composition by a hydrosilylation reaction. The liquid cross-linkable composition can be dispersed in water by using devices such as homomixers, paddle mixers, Henschel mixers, homodispersers, colloid mills, impeller agitators, homogenizers, in-line continuous action emulsifiers, ultrasonic emulsifiers, and vacuum kneaders.
There are no specific limitations with regard to the amount of added water used in the process, but it is preferred that it be in the range of 5 weight percent to 99 weight percent, preferably 10 to 80 weight percent, based on the total weight of the emulsion.
To create stable dispersions of the liquid cross-linkable composition in water, it is preferred to use one or more of the above described cationic surface-active agents, anionic surface-active agents, zwitterionic surface-active agents, or nonionic surface-active agents. The use of a nonionic surface-active agent is preferred. There are no specific limitations with regard to the amount of surface-active agent used, however it is preferred that it be present in the range of 0.1 parts by weight to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the liquid cross-likable composition containing the non-crosslinkable silicone oil or organic oil.
The liquid cross-linkable composition dispersed in water can be cross-linked by hydrosilylation carried out by heating the emulsion of liquid cross-linkable composition, or by allowing it to stand at room temperature.
The process for preparing the silicone oil composition or the organic oil composition consists in removing water from the emulsion of the silicone oil or organic oil. Water can be removed from the oil emulsion by air drying, hot-air drying, vacuum drying, or heat drying. The resulting silicone oil composition or organic oil composition will contain a cross-linked product that is well dispersed in the silicone oil or organic oil. The composition can be in the form of a liquid, cream, paste, or grease. The cross-linked particles contained in the drops of silicone oil or the drops of organic oil in such silicone oil compositions or organic oil compositions should have an average diameter of from 0.05 xcexcm to 100 xcexcm, preferably 0.1 xcexcm to 100 xcexcm, more preferably 0.1 xcexcm to 50 xcexcm. Such an oil composition can be used as a lubricating agent, or it can be used as an agent to impart lubricating properties. In addition, it has applications as an additive for cosmetics, dyes, plastics, and organic resins.